Electronic data processing systems such as personal computers have become increasingly available for general use as costs have decreased and capabilities have increased. Advancements in technology have also resulted in portable laptop computer systems having decreased size, weight, and cost and having increased capabilities. The size and weight of laptop computers significantly decreased when designers of laptop computer monitor displays were able to take advantage of advancements in liquid crystal display (LCD) technologies.
Graphic user interface (GUI) software allows data to be displayed on the screen, of a display unit (such as a computer monitor) in one or more portions of the screen. These portions of the screen, usually rectangular in shape, are referred to as windows. Two or more windows on a computer monitor screen may or may not overlap. When multiple windows are present on a computer monitor screen, it is desirable to be able to highlight one or more of the windows to cause the selected highlighted windows to be seen more easily than the other windows that are not selected.
It is desirable to be able to highlight a window that is displaying a program of television entertainment or a motion picture while other non-highlighted windows simultaneously display other data. It is desirable to highlight the window with an entertainment program so that the viewer is less distracted by other images that may be simultaneously displayed in the other non-highlighted windows.
Methods for highlighting a portion of a display screen (such as a window) in a standard cathode ray tube (CRT) television monitor are well known in the art. One method involves highlighting the selected portion by making it brighter than the other portions of the display screen. This is done by overdriving the beam current in the area of the screen that contains the selected-portion to be highlighted. This provides a level of brightness in the selected portion that is higher than the level of brightness in the other areas.
This method can not be used in LCD displays because 1) the maximum brightness on an LCD screen is limited to the brightness of the backlight times the maximum light transmission of the LCD screen, and 2) the maximum brightness of each window is usually chosen to be the same throughout the LCD screen.
It is known in the television industry that increasing the color temperature of the white portion of a television image makes the television image appear to be brighter than other areas of the same emitted radiant energy of lower color temperature. The National Television Standards Committee (NTSC) standard for television monitors specifies a white color temperature of 6,770° K. Industry practice is to use a white color temperature of 6,500° K for television studio monitors. It is common practice, however, to raise the white color temperature in order to make the screen appear brighter. The white color temperature in cathode ray tube (CRT) television monitors is often set to be equal to a relatively high color temperature between 8,000° K and 15,000° K. This makes the white color in the resulting image appear to be brighter without increasing the luminance of the image.
There is a need in the art for an improved system and method for highlighting a selected portion of a display screen of a display unit. In particular, there is a need for an improved system and method for causing a selected portion of a display screen to appear brighter than other areas of the display screen.